Introduction

A number of radiographic
techniques have been described for examining the upper G.I. tract. The
double-contrast (DC) examination, popularized by the Japanese, requires a
small amount of high-density barium suspension to coat the mucosal surface
and air or CO2 gas to distend the lumen. This technique gives excellent
definition of the lesser and greater curvatures and the posterior wall of
the stomach; however, satisfactory DC images of the anterior wall of the
distal stomach and duodenum are very hard to obtain. Even before the
development of the DC procedure, it was known that the anterior wall of
these structures could be demonstrated en face by filling the stomach and
duodenum with a low-density barium suspension and applying graded
compression to permit the examiner to “see through” these viscera—the
so-called single-contrast graded-compression (SCGC) technique.

The biphasic-contrast examination, introduced in 1977 by Op den Orth, is a
method which combines the best features of the DC and the SCGC
techniques in one diagnostic procedure. This method is best performed with a
single barium suspension that can provide excellent mucosal coating during
gaseous distention in the DC phase of the study and also sufficient
transparency to permit “see through” of the contrast agent during the SCGC
phase. To achieve these goals, we have developed a medium-density barium
suspension which can be administered simultaneously with a gas-producing
agent in the form of a cold, carbonated drink (“bubbly barium”), which is
dispensed from a soda siphon (Soda King, Model 100 Home Soda-Fountain
Siphon, Kidde, Inc., Mebane, NC).